Lift magnet for structural steel beams



June 30, 1964 A. FREEMAN LTTT MAGNET FOR STRUCTURAL STEEL BEAMs 2 Sheets-Sheet l Filed Aug. 22, 1962 INVENTOR ALFRED FREEMAN E, M26/Md Attorney A June 30, 1964 A. FREEMAN LIFT MAGNET FOR STRUCTURAL STEEL BEAT/1s ALFRED FREEMAN mzb Alforney 2 Sheets-Sheet 2 Filed Aug. 22, 1962 rof the invention.

United States Patent 3,139,563 LllF'Ir MAGNET FOR n Alfred Freeman, Crete Township, Will County,vlll., as-

signor to United States Steel Corporation, a corporation of NewJersey y Filed Aug. 22, 1962, Ser. No. 218,746 3 Claims. (Cl. 317-464) The present invention relates generally to lift magnets and more particularly toan improved electro-magnet especiallysuitablefor lifting singlelengths of structural steel beams.

Structural steel beams such asangle beams, H beams, I beams, channels and the like are conventionally produced by rolling on structural rolling mills and are delivered from the finishing end of the mill to skid beds or chain conveyor beds where they are laid side-by-side. The beams are then picked up singly and transported to a storage area where they are stacked in nested piles arranged in rows.

A conventional lift magnet was utilized to carry the beams from the skid or chain conveyor bed and pile them in the storage area. Prior to my invention thiskoperation was excessively time consuming and hazardous due to the difficulty encountered in picking up only a single beam at a time wtihout disturbing or magnetically attracting one or more adjacent beams. It was also very difficult to remove one beam at a time from a pile of rnested beams with a conventional lift magnet when it was desired to move the beams from the storage area to prepare a shipment or for further processing.

STRUCTURAL STEEL nanars It is, accordingly, the primary object of my invention y to provide an electro-magnet of unique design whereby single structural steel beams can be picked up from a group of beams and piled in a nesting manner, `or conversely, a single beam can be picked up from a nested pile without disturbing adjacent beams.

This and othery objects will become more apparent after referring to the following specification and attached drawings, in which:

FIGURE l is an elevational view of the magnet of the invention; p

FIGURE 2 is a cross-sectional view taken along the line II-II of FIGURE l;

FIGURE 3 is a view similar to FIGURE l of a modified embodiment of the magnet of the invention; and

FIGURE 4 is a cross-sectional View taken along the line IV--IV of FIGURE 3.

Referring for the present to FIGURES 1 and 2,'there is shown an embodiment of my invention particularly adapted for use in handling structural steel angle beams. Reference numeral 2 designates the core of the magnet Core 2, which may be made of low carbon steel, soft iron, laminated iron orthe like, is elongated and horizontally disposed. An exciting winding 4 is wound around the core 2 between a pair of pole plates 6 which are rigidly affixed to two opposite sides of the core 2 in parallel relation by nut and bolt means S. Pole plates 6 extend parallel with the core 2 and project beyond the periphery of the winding 4. The lower edges of ther pole plates are provided with beveled inner surfaces 10 which function as poles adapted to engage the back of an angle beam A, as best shown inFIGURE 2.

A horizontally disposed separator plate 12k of nonmagnetic stainlessV steel orother non-magnetic material apical portion of the angle beam, as best shown in FIG- y 3,139,563 lliatentecl June 30, 1964 ,ICC

rator plate 12 serves as a guide or positioner and also functions 'to rigidity and strengthen the lower portions of the pole plates 6. The plate 12 is made of nonmagnetic material so as to prevent flow of magnetic flux between the bottom portions of the pole plates. y

A pole shoe 18 of non-magnetic stainless steel or other non-magnetic material is aflixedto thevouter surface of the lower edge of each of thepole plates 6 by means'of flat head screws 19. Each pole shoe 18 extends outwardly and downwardly from its respective pole plate at an `angle continuous with the beveled face of the prole 10. The pole shoes aid in centering the magnet relative to the back of an angle beam to be lifted. The pole shoes also serve to magnetically insulate the outer surfaces of lower edges of the pole plates so that adjacent angle beams are not disturbed when an angle beam is lifted from a group of similar beams lying side-by-side.

A pin 20 of non-magnetic material projects transversely through the upper portion of the pair of pole plates 6 adjacent opposite ends thereof. A hanger rod 22 is rotatably mounted by one end on each of the pins 20 between the pole plates and extends upwardly therefrom to project above the upper edges of the pole plates. The upper end of Aeach hanger rod is connected with a hoist beam (not shown) suspended from an overhead lift crane (notshown) whereby the magnet can be manipulated to handle the structural steeljbeams.

An electric plug 24 connected with a source of electrical current is mounted on one end of one of the pole plates 6 by means of an L-shape brass bracket 26. Leads W1 and W2 of the winding 4 are attached to terminals' 28 on the bracket 26.

FIGURES 3 and 4 illustrate a modified embodiment of the lift magnet of the invention which is especially suitable for handlingstructural steel beams having a web and flange fillets at each end of the web, such as id beams, I beamsQchannels and the like. FIGURE 4 shows the modified magnet of the invention lifting a channel beam C.

Similarly to the lift magnet of the invention iirst described above, the modified embodiment thereof, consists of a horizontallydisposed elongated magnet'core 2', an exciting winding 4 wound around'the core, and pole plates 6 atlixed one to each of two opposite sides of the core by nut and boltmeans 8. project downwardly beyond the winding 4' in spaced parallel relation. Ahorizontally disposed iiat separator plate y30 of non-magnetic stainless steel or similar nonmagnetic material is interposed between the pole plates above the lower edges thereof. The separator plate 30 extends along the length of the lower edges of the pair of pole plates 6 and is fastened to them by flat head screws 14'. As best shown in FIGURE 4, the bottoms or pole faces 32 of the pole plates 6 are flat and not beveled so asto be able to engage the at web of a structural steel beam. The horizontal distance between the outer surfaces of the pole plates 6 is less than the j flux-limiting pole sizes inthat the thicknesses of the pole distance between the iiange fillets of the narrowest flanged structural beam to be handled.

Other parts of the modified lift magnet of the invention are similar to corresponding parts of the lift magnet iirst described above and have been designated with the like re'ference'characters but primed. The magnet of the invention is provided wtih inherent faces (10 and 32) are each of the same order of magnitude as the thinnest structural beam to be handled. In

other words, the width of the pole face of lthe magnet is no greater than the iiange thickness of any angle beam to be handled or no greater than the web thickness of y The pole plates 6' 3 any H beam, I beam or channel to be handled. Also, the ampere turns of the exciting winding (4 and 4') is such as to produce only moderate saturation of the poles. This prevents the forcing of excessiverux in thin beams and thus reduces the fringing effect which would disturb adjacent beams when piling. The length of the magnet is determined by the maximum beam weight which is to be handled.

In operation, electrical current is passed to the winding through the electric plug and terminals of the lift magnet of the invention to energize the magnet to pick up a beam. The magnet is de-energized by cutting oft the current to the Winding to release a beam carried thereby.

While two embodiments of my invention have been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. A magnet for lifting a single structural steel beam comprising a horizontally-disposed elongated magnet core, 20

to each other, the lower edge of each of said pole plates being beveled along its inner surface to form a pole face.

2. A magnet as defined by claim 1 in which a separator plate of non-magnetic material is interposed between said pole plates intermediate said winding and the lower edges of said pole plates, said separator plate being substan- `tially inverted V shape in cross-section and extending parallel with said pole plates.

3. A magnet as defined by claim 2 including an elongated pole shoe of non-magnetic material rigidly alixed to the outer surface of the lower edge of each pole plate, the lower edge of each of said shoes extending outwardly and downwardly from its respective pole plate at an angle continuous with the beveled inner'surface of the lower edge of said respective pole plate.

References Cited in the file of this patent UNITED STATES PATENTS 762,759 Reuter June 14, 1904 2,347,170 Brown et al. Apr. 25, 1944 2,546,010 McSherry Mar. 20, 1951 2,572,999 Elliott Oct. 30, 1951 `2,729,344 Birchall Jan. 3, 1956 3,068,790 Speaker Dec. 18, 1962 

1. A MAGNET FOR LIFTING A SINGLE STRUCTURAL STEEL BEAM COMPRISING A HORIZONTALLY-DISPOSED ELONGATED MAGNET CORE, A PAIR OF POLE PLATES AFFIXED ONE TO EACH OF TWO OPPOSITE SIDES OF SAID CORE AND EXTENDING PARALLEL THEREWITH, AND AN EXCITING WINDING WOUND AROUND SAID CORE BETWEEN SAID POLE PLATES, SAID POLE PLATES EXTENDING DOWNWARDLY BEYOND SAID WINDING AND CORE IN SPACED PARALLEL RELATION TO EACH OTHER, THE LOWER EDGE OF EACH OF SAID POLE PLATES BEING BEVELED ALONG ITS INNER SURFACE TO FORM A POLE FACE. 